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Thursday, November 3, 2011

Xenon detection - Fukushima Daiichi No. 2 - Thursday morning update

TEPCO's latest press release includes the following statement:

-We found a possibility to detect short-half-life radionuclide such as Xe-133 and Xe-135 according to our radionuclide analysis sampled on November 1 by the gas management system of the reactor containment vessel. We continued to monitor the temperature, pressure and data from monitoring post and there was no significant fluctuation from those data. As we can't deny a possibility of fission reactions, we decided to start injecting boric acid water from reactor feed water system at 2:48 am on November 2 and stopped it at 3:47 pm on the same day. At around 7:20 pm on the same day, Japan Atomic Energy Agency evaluated that the TEPCO's analysis result of the short-half-life radionuclide such as Xe-133 and Xe-135 detection was valid. We consider that they were generated by the spontaneous fission.

This press release (above) is the 10:00 AM November 3 press release.

HOWEVER, some Japanese media are carrying a TEPCO RETRACTION of some previous information, saying instead that the xenon detected in the primary containment has been formed from spontaneous fissions of curium-242 and curium-244.

Other statements have clarified any possible criticality - TEPCO stating clearly now that criticality was NOT achieved. (This author has said this many times in the last two days.) The xenon must be the result of spontaneous fission, TEPCO indicates.

There will be much clearer information available later today in all likelihood.